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[disc]

Yeah, the idea is that a modern torpedo protection system will stop flash and fragments from getting to the magazines, even if flooding is not stopped entirely.

Older and smaller designs were vulnerable, so I think a deflagration chance should still be there for lesser anti-torpedo belts -- think HMS Royal Oak.

 

A weakness with the current system is that repeat hits to the same spot do no extra damage. Torpedo belts are ablative, so more hits would have a compounding effect.

There's little implementation of flooding instability, either, a major (perhaps the most important) cause of loss.

[madham82]

44 minutes ago, disc said:

Yeah, the idea is that a modern torpedo protection system will stop flash and fragments from getting to the magazines, even if flooding is not stopped entirely.

Older and smaller designs were vulnerable, so I think a deflagration chance should still be there for lesser anti-torpedo belts -- think HMS Royal Oak.

 

A weakness with the current system is that repeat hits to the same spot do no extra damage. Torpedo belts are ablative, so more hits would have a compounding effect.

There's little implementation of flooding instability, either, a major (perhaps the most important) cause of loss.

Really wish they would implement deflagration for the magazines, since it would make damage control items that much more critical, but I have a feeling they are still tweaking damage modeling below decks. 

[Masonator]

On 4/4/2020 at 4:13 PM, madham82 said:

If you have had a ammo detonation with Anti-torp V and a capital ship sunk from a single hit, then it is definitely broke. We broke it out in another thread, and there is no record of any capital ship (i.e. actually has some kind of torpedo protection) being sunk because of a torpedo ammo detonation. There really isn't any proof any type of ship with a good torpedo bulge /protection ship having it occur either. They should definitely be able to cause it to DDs and most CL/CAs, and there are multiple examples of it. By a large margin, there are more examples of ammo detonations occuring because of fire than any single factor, but this isn't modeled yet. 

I personally have only had it happen in game on ships without any torpedo protection. 

It's so utterly broken that the torpedo literally hit me at the extreme aft end of the ship (I'm talking in line with the rudderpost, or even further abaft it), and still caused an ammo detonation that destroyed an otherwise-undamaged battlecruiser, battleship, and heavy cruiser in one hit each. All three ships were taken out by the exact same type of hit. It's a complete load of shite.

[Steeltrap]

On 4/5/2020 at 4:31 AM, arkhangelsk said:

Second, my attempt to escort the enemy and give them hydroacoustic support did not seem to work, with the torpedoes of the first wave (20 of them) being detected extremely late, leading to the unjustified loss of British battleship.

AI either needs to learn to install hydrophones when the opportunity is present or manoeuvre ships out of harm's ways based on hydrophonic detections.

If the game is allowing hydrophones to detect ANYTHING while the ship mounting it is moving at any sort of speed, to the best of my knowledge that's [redacted, lol].

I AM aware of interesting cases of using hydrophones, particularly USS Tang's habit of lying effectively 'hove to' on the surface at night (diesels were off, obviously; if any manoeuvre were necessary it was done using battery power) using its hydrophone that was lowered from the hull to listen for any approaching threat, and that was proven to work (from Dick O'Kane's "Clear the Bridge").

Similarly, Dick O'Kane retells the occasion where they were hunted by an IJN DD using listening gear. They were at depth and had very minor seepage. He points out that whenever they had to run the pumps briefly to expel accumulated water, the DD would detect them and spring to life. Otherwise it couldn't hear them. Point is THE DD WAS STATIONARY.

Does anyone have a source suggesting surface mounted passive listening gear was of any value if the ship carrying it is travelling above perhaps 10 knots at best? That's before we consider the fact a torpedo is going to be emitting relatively high frequency sound AND travelling close to the surface.

Perfectly fine with the idea of getting such info when the ship detecting it is operating at speeds where the detection is reasonable/reliable. At ANY speed? No, sorry, not buying it.

I really DO NOT want this game to start adding stuff that "smells of WoWS", and the idea that hydrophones will improve torpedo detection when the platform is running around at 20+ knots is exactly that in my mind.

Thoughts, anyone?

[Edit: I am aware of reports about hydrophone warnings of torpedoes on the Scharnhorst class of WW2, although there, too, they're rather unreliable and, in at least two occasions, the torpedoes were spotted from foretop lookouts before any hydrophone report. I also found this interesting document re the GHG 'passive array' mounted in the bows of German U-boats; I imagine the capital ships had something similar, but have had trouble getting any sensible performance data for them on those ships]

Edited April 7, 2020 by Steeltrap

[Steeltrap]

On 4/6/2020 at 6:39 AM, Masonator said:

It's so utterly broken that the torpedo literally hit me at the extreme aft end of the ship (I'm talking in line with the rudderpost, or even further abaft it), and still caused an ammo detonation that destroyed an otherwise-undamaged battlecruiser, battleship, and heavy cruiser in one hit each. All three ships were taken out by the exact same type of hit. It's a complete load of shite.

Well, I hate to say "I told you so" (not YOU, obviously), but I predicted exactly this.

The example you give is directly due to the damage model having magazines OUTSIDE where the transverse bulkhead of the 'citadel' would start.

Suggested this change ought to be dropped until that armour/damage model issue is addressed.

With the system as it is, your experience is all but inevitable; it's exactly the same as sinking ships with lightly armoured 'external' zones with 2"/50mm guns (!!!) due to their causing ammo explosions.

I'm fine with the mechanic in principle, but it makes VERY little sense when you cannot build your ship to guard against it due to that compartmentalisation/armour shortcoming.

Armour/compartmentalisation/damage model interactions are THE big things needing attention IMO. I'm not especially interested in anything else that might be added until THOSE are addressed substantially.

Cheers

[arkhangelsk]

6 hours ago, Steeltrap said:

[Edit: I am aware of reports about hydrophone warnings of torpedoes on the Scharnhorst class of WW2, although there, too, they're rather unreliable and, in at least two occasions, the torpedoes were spotted from foretop lookouts before any hydrophone report. I also found this interesting document re the GHG 'passive array' mounted in the bows of German U-boats; I imagine the capital ships had something similar, but have had trouble getting any sensible performance data for them on those ships]

To which I'll add how Prinz Eugen was able to hear the screws of approaching British battleships, and as far as anyone can tell, she did not stop to hear them. Against ships and torps, it seems the sonars do work even when the ships are at speed.

Also, we might add that any time a T-V homes in on an escort ... torpedo is moving at over 20 knots, the sensor is utterly puny. But it finds something to home on.

In any case, the game's position right now is that hydrophones are useful in detecting torpedoes. And considering all the screaming about overly effective destroyers, I suspect that will not go away. Anyway, since that is the position of the game, should not the AI be taught to use them so they are less of a sitting duck?

Edited April 7, 2020 by arkhangelsk
Add T-V

[Hangar18]

On 3/31/2020 at 10:56 PM, Masonator said:

Torpedoes detonating magazines is the dumbest addition to this game yet. I can go into custom battles, set myself up with 4 maxed-out super-battleships at 130,000 tonnes displacement, Anti-Torp V torpedo belts, bristling with guns, and face off against nothing but 6 destroyers. The destroyer squadron will win 10 times out of 10 because the AI will always default to 24" torps as soon as they're available, which are practically guaranteed to detonate magazines and one-shot whatever ship they hit, every time. It completely ruins the pace of the game and is positively infuriating to try and deal with.

 

For reference, here's a picture of a custom battle I set up where a Dreadnought battleship, one heavy cruiser, one light cruiser, five destroyers, and a recreation of HMS Hood engaged a German transport fleet escorted by two heavy cruisers, one light cruiser, a Dreadnought battleship, and 6 destroyers. Literally one single  torpedo hit from a destroyer struck Hood on the hello kittying rudder, somehow magically detonated her magazines, and sunk her in one hit. Minutes later the exact same thing happened to my battleship, then again to my heavy cruiser. It's complete and utter bullshit.

did you take *any* improvements to reduce the odds of a magazine detonation? barbettes, citadel? how much ammo did you bring? did you have torpedoes fitted?

[disc]

@Steeltrap I often wonder the same thing. Were hydrophones effective in detecting and tracking torpedoes? I'd love to know of any good references on the subject.

A central question I have is whether hydrophones were capable of independent search. Would they find something if not pre-alerted? I think their effectiveness at night -- ie when it is unclear if enemies are even in the area -- may be the best measure of this. A vast number of ships equipped with hydrophones were sunk by torpedoes, of course, so  they were no panacea. But how many ships managed to avoid torpedoes by using their sound gear?

For American hydrophones, I don't know. Supposedly the 1945 WFA set could detect torpedoes, but I don't know about earlier sets. No information given in US Naval Weapons. Best reference I can find is that MV hydrophones mounted in surface ships could detect other surface ships while in motion.

An important difference from the game is that passive sonar would not generate reliable ranges, only bearings. It might be clear that a contact was approaching or receding, though, so over time, in combination with bearing rates and loudness, rough estimates could be prepared. Active sonar would be too directional to be of particular use in search, I think, but they might conceivably be useful in tracking already spotted torpedoes.

 

 

[madham82]

2 hours ago, Hangar18 said:

did you take *any* improvements to reduce the odds of a magazine detonation? barbettes, citadel? how much ammo did you bring? did you have torpedoes fitted?

That brings up a good point. Barbette size shouldn't be used to calculate the chance of torpedo detonation. Anti-torpedo protection should have it's own ammo detonation reduction value.  

12 minutes ago, disc said:

An important difference from the game is that passive sonar would not generate reliable ranges, only bearings. It might be clear that a contact was approaching or receding, though, so over time, in combination with bearing rates and loudness, rough estimates could be prepared. Active sonar would be too directional to be of particular use in search, I think, but they might conceivably be useful in tracking already spotted torpedoes.

Exactly what I mentioned in another thread about adding them to BBs. We should only get a message alert with the bearing from the ship detecting them. The battle log someone shared from Scharnhorst clearly showed only a bearing given. It really would be helpful, since you could tell the lookouts to concentrate on that bearing, but you wouldn't know the course and speed without more information like you mentioned. You are still down to the Mk1 eyeball being the best means of detection and evasion. 

[Hangar18]

2 hours ago, madham82 said:

Barbette size shouldn't be used to calculate the chance of torpedo detonation

why would thicker armored barbettes not be part of that calculation...

[disc]

On battleships, barbettes were largely above the waterline. Centerline turrets were typically some distance from the ship side, but obviously this was untrue for wing turrets. A torpedo was unlikely to hit barbettes directly on a battleship. Their main advantage might be blocking rare fragments, for which very heavy armor would be overkill.

On cruisers, the barbette tubes may extend down to a wholly underwater magazine. Combined with a narrow beam, the lower reaches on barbettes could be close to the immediate blast zone. Of course, only some cruisers had this arrangement, others having the magazine box extend up to the waterline, so that barbette armor would be less relevant.

So barbette armor might be somewhat useful on some cruisers against torpedoes, but less so on bigger ships, where only frag protection would really be needed.

Of all things, strong deck armor should reduce torpedo damage. It tends to choke off damage and keeps it from affecting upper parts of the ship.

[Hangar18]

6 hours ago, disc said:

On battleships, barbettes were largely above the waterline. Centerline turrets were typically some distance from the ship side, but obviously this was untrue for wing turrets. A torpedo was unlikely to hit barbettes directly on a battleship. Their main advantage might be blocking rare fragments, for which very heavy armor would be overkill.

On cruisers, the barbette tubes may extend down to a wholly underwater magazine. Combined with a narrow beam, the lower reaches on barbettes could be close to the immediate blast zone. Of course, only some cruisers had this arrangement, others having the magazine box extend up to the waterline, so that barbette armor would be less relevant.

So barbette armor might be somewhat useful on some cruisers against torpedoes, but less so on bigger ships, where only frag protection would really be needed.

Of all things, strong deck armor should reduce torpedo damage. It tends to choke off damage and keeps it from affecting upper parts of the ship.

doesnt seem so

[disc]

Poor choice of words. What I mean is the heavy barbette armor was only above the waterline. Iowa's main armored deck was the second deck, the one just under the main (topside) deck. The barbette structure continued down to the bottom, but the heavy barbette armor was only above the armored second deck.

There was some internal armor. It was 3in from the 2nd to the 3rd deck, with I believe another internal structural ring of 1.5in. It was 1.5in below that. The 3in ring was probably there as a support to the armor above it and as a splinter guard for penetrating bombs and shells.

Here's a nice picture. The red number 7 sits on the second deck. The shells are inside the barbette, but the more volatile charges are outside of it, so flash from a turret fire couldn't get to them.

If a torpedo impacted abreast Iowa's turret, and the blast penetrated the torpedo belt, then it could hit the powder charges in the magazine and detonate them. The 3in to 1.5in internal barbette armor, further inboard, would only protect the handling rooms and stop fragments flying the whole width and hitting the other side. I suppose that you could argue this internal ring was therefore beneficial against torpedoes, but the heavy armor above it was of no consequence.

[madham82]

13 hours ago, Hangar18 said:

why would thicker armored barbettes not be part of that calculation...

Think about it this way, if a torpedo already broke through the torpedo protection and made it through the armor belt (which would cover the barbettes), then it could reach the magazine directly. This never happened though, probably because there wasn't that kind of explosive power in them. You are going through both empty/ballast space, then assuming you have enough kinetic energy to blast through the belt armor too. You would need something like a bunker buster bomb, but in torpedo form. 

Now I'll buy what @disc said about something like a cruiser (which doesn't have torpedo protection) taking a hit directly to the barbette, but it wouldn't destroy the ship outright. Given the location of magazines on most of these ships, there's a better chance it would hit the magazine directly anyway which is the real threat.

Honestly, unless the crew are doing some like the British did at Jutland, or the engineers did not install any safety systems between the turret ammo handling and magazine then there really is no chance of a hit to the barbette causing a catastrophic detonation. A smaller detonation, of the powder being stored in the barbette or destruction of the turret itself definitely. That's really the only time the armor thickness of it would matter. I assume this is what the devs were after implementing it. 

From my experience in the game, it really is useless to change it. I have not used it on any of my builds. I haven't even had one have a barbette destroyed, though I have done it to the AI once. It's a pretty rare hit from what I seen so far. You are more likely to hit the turret. 

[Hangar18]

On 4/8/2020 at 9:22 AM, madham82 said:

Think about it this way, if a torpedo already broke through the torpedo protection and made it through the armor belt (which would cover the barbettes), then it could reach the magazine directly. This never happened though, probably because there wasn't that kind of explosive power in them. You are going through both empty/ballast space, then assuming you have enough kinetic energy to blast through the belt armor too. You would need something like a bunker buster bomb, but in torpedo form. 

Now I'll buy what @disc said about something like a cruiser (which doesn't have torpedo protection) taking a hit directly to the barbette, but it wouldn't destroy the ship outright. Given the location of magazines on most of these ships, there's a better chance it would hit the magazine directly anyway which is the real threat.

Honestly, unless the crew are doing some like the British did at Jutland, or the engineers did not install any safety systems between the turret ammo handling and magazine then there really is no chance of a hit to the barbette causing a catastrophic detonation. A smaller detonation, of the powder being stored in the barbette or destruction of the turret itself definitely. That's really the only time the armor thickness of it would matter. I assume this is what the devs were after implementing it. 

From my experience in the game, it really is useless to change it. I have not used it on any of my builds. I haven't even had one have a barbette destroyed, though I have done it to the AI once. It's a pretty rare hit from what I seen so far. You are more likely to hit the turret. 

Many cruisers had a TDS. The IJN CA's, the KM CA's, all had em.

There was Plenty of explosive power in them, none of the TDS at the time were very good. The Italians failed,the Germans failed, the Japanese failed, and the americans never really got tested, but you see where this trend is going. Flooding the ballast will not always help. You don't even need a 24" torpedo to see this. You can look no further than 4 21" torpedoes that capsized shinano. That's through the TDS, through the 400mm belt.

Those torpedoes carry a warhead of 292 kg. Now lets look at the 24" type 93: 490kg. 

(technically these are 1.5, and 1.07 times more powerful, this is TNT weight)

Lets compare this to the explosive power of the largest guns ever put to sea. The 460mm guns of the yamato deliver explosive charges of 62kg (HE), 34kg (AP). Now credit where its due, the AP shell will explode closer to the magazine. Giving the benefit of the doubt, lets say the torpedo doesn't simply explode underneath the ship, which would put this massive warhead very close to the magazines. The TDS of the NC was designed to hold up to 320kg. Theres about 30 feet or so from the A turret barbette to possible impact site.

How safe are you feeling with an amount of TNT equivalent to an adult grizzly bear exploding 30 feet away from things that do not react well to explosions. How safe are you feeling if it goes off beneath the ship, possibly 2 rooms and a double bottom away?

[madham82]

18 hours ago, Hangar18 said:

Many cruisers had a TDS. The IJN CA's, the KM CA's, all had em.

Think you misinterpreted my statement. I said in the example of a cruiser without a protection system would be very vulnerable to a magazine detonation. Also we should point out there is a difference in torpedo protection systems. Torpedo bulkheads and torpedo bulges. I don’t believe many (if any) CAs used bulges. The small torpedo bulkheads used on my CAs would not be near as effective as a true system which uses both like on a modern BB design.

 

18 hours ago, Hangar18 said:

There was Plenty of explosive power in them, none of the TDS at the time were very good. The Italians failed,the Germans failed, the Japanese failed, and the americans never really got tested, but you see where this trend is going. Flooding the ballast will not always help. You don't even need a 24" torpedo to see this. You can look no further than 4 21" torpedoes that capsized shinano. That's through the TDS, through the 400mm belt.

What point are you trying to make here? All I said was to punch through the empty/flooded space of a torpedo bulge, then make it through the actual belt armor to hit centrally located main magazines and cause an explosion is beyond remote. That bulge (while it may not prevent flooding and loss of stability) is perfect for preventing the torpedo from exploding in contact with the armor belt/hull, thereby significantly reducing the chance something reaches the magazine. You have a great example of this by looking at damage caused by USS Skate on Yamato. From the Captain’s report:

"A hole about 16ft (5m) deep extending downwards from the top of the bulge connection and 82ft (25m) in length between frames 151 and 173. Water flooded into No 3 turret upper magazine from a small hole in the longitudinal bulkhead caused by caving in of the waterline armor"

Note this was a single torpedo and what happened to the magazine? A flood, the safest outcome for any hit near the magazine.

The Shinano (and the Yamatos) all suffered from a compromised torpedo protection system that made them extremely vulnerable on the bow and stern from what I remember. In this game, we are assuming 100% reliability from our designs. Maybe that’s unrealistic, but that’s the way the game models it. So using them as an example of how a torpedo protection system doesn’t work well isn’t useful.

You can also use the hit on the USS North Carolina as another example. It hit directly under the turret, but by all accounts, the damage was normal for what the designers expected. Again, my point in this thread is barbette armor should not be a factor in ammo detonations from torpedo hits. Anti-torpedo selections should reduce it. To what degree, that’s debatable.     

18 hours ago, Hangar18 said:

Lets compare this to the explosive power of the largest guns ever put to sea. The 460mm guns of the yamato deliver explosive charges of 62kg (HE), 34kg (AP). Now credit where its due, the AP shell will explode closer to the magazine. Giving the benefit of the doubt, lets say the torpedo doesn't simply explode underneath the ship, which would put this massive warhead very close to the magazines. The TDS of the NC was designed to hold up to 320kg. Theres about 30 feet or so from the A turret barbette to possible impact site.

Comparing torpedo explosives to shells really is pointless, they impact their targets in two completely different ways and locations (for the most part). Torpedoes by far are more devastating. No one is saying otherwise. It only takes a handful to sink even the largest capital ship, compared to hundreds of shell hits. But at the same time, no capital ship with a sound torpedo protection system I know of was ever sunk by a single torpedo. Nor did any suffer a catastrophic ammo detonation from the direct impact of a torpedo (fires started by a hit are another story). Many were sunk by flooding/capsizing. I and for one am not advocating torpedo tanking, but something the size of a Yamato or bigger also should be able to shrug off multiple hits with a good protection system. 

18 hours ago, Hangar18 said:

How safe are you feeling with an amount of TNT equivalent to an adult grizzly bear exploding 30 feet away from things that do not react well to explosions. How safe are you feeling if it goes off beneath the ship, possibly 2 rooms and a double bottom away?

Safe (in terms of the ship surviving) considering there are no examples I have seen or heard. Then the examples I provided of Yamato and North Carolina both taking hits under turrets without any real threat to the magazine (or explosions in the barbettes). But this is really beside the point since we were talking about barbette armor. How much powder is stored in a barbette? Enough to sink a ship, not even close. Could you have a flash that destroys the turret by igniting the powder inside? Possibly, but the game isn’t simulating that. 

Now if we get a detailed below decks damage model, then things like this become reasonable. But this whole conversation goes back to Masonator’s losing a BB with max torpedo protection (or at least that’s way it came off) to a single torpedo. It just didn’t happen and shouldn’t with game modeling as is. I can only hope the devs do give us a better model here, since magazine detonation due to fire effects happened far more often.  

 

[Masonator]

On 4/7/2020 at 3:13 PM, Hangar18 said:

did you take *any* improvements to reduce the odds of a magazine detonation? barbettes, citadel? how much ammo did you bring? did you have torpedoes fitted?

Barbette IV, Citadel IV (turtleback), regular ammo load, no torps installed. It's completely broken.

[Hangar18]

On 4/10/2020 at 3:14 PM, madham82 said:

Think you misinterpreted my statement. I said in the example of a cruiser without a protection system would be very vulnerable to a magazine detonation. Also we should point out there is a difference in torpedo protection systems. Torpedo bulkheads and torpedo bulges. I don’t believe many (if any) CAs used bulges. The small torpedo bulkheads used on my CAs would not be near as effective as a true system which uses both like on a modern BB design.

 

What point are you trying to make here? All I said was to punch through the empty/flooded space of a torpedo bulge, then make it through the actual belt armor to hit centrally located main magazines and cause an explosion is beyond remote. That bulge (while it may not prevent flooding and loss of stability) is perfect for preventing the torpedo from exploding in contact with the armor belt/hull, thereby significantly reducing the chance something reaches the magazine. You have a great example of this by looking at damage caused by USS Skate on Yamato. From the Captain’s report:

"A hole about 16ft (5m) deep extending downwards from the top of the bulge connection and 82ft (25m) in length between frames 151 and 173. Water flooded into No 3 turret upper magazine from a small hole in the longitudinal bulkhead caused by caving in of the waterline armor"

Note this was a single torpedo and what happened to the magazine? A flood, the safest outcome for any hit near the magazine.

The Shinano (and the Yamatos) all suffered from a compromised torpedo protection system that made them extremely vulnerable on the bow and stern from what I remember. In this game, we are assuming 100% reliability from our designs. Maybe that’s unrealistic, but that’s the way the game models it. So using them as an example of how a torpedo protection system doesn’t work well isn’t useful.

You can also use the hit on the USS North Carolina as another example. It hit directly under the turret, but by all accounts, the damage was normal for what the designers expected. Again, my point in this thread is barbette armor should not be a factor in ammo detonations from torpedo hits. Anti-torpedo selections should reduce it. To what degree, that’s debatable.     

Comparing torpedo explosives to shells really is pointless, they impact their targets in two completely different ways and locations (for the most part). Torpedoes by far are more devastating. No one is saying otherwise. It only takes a handful to sink even the largest capital ship, compared to hundreds of shell hits. But at the same time, no capital ship with a sound torpedo protection system I know of was ever sunk by a single torpedo. Nor did any suffer a catastrophic ammo detonation from the direct impact of a torpedo (fires started by a hit are another story). Many were sunk by flooding/capsizing. I and for one am not advocating torpedo tanking, but something the size of a Yamato or bigger also should be able to shrug off multiple hits with a good protection system. 

Safe (in terms of the ship surviving) considering there are no examples I have seen or heard. Then the examples I provided of Yamato and North Carolina both taking hits under turrets without any real threat to the magazine (or explosions in the barbettes). But this is really beside the point since we were talking about barbette armor. How much powder is stored in a barbette? Enough to sink a ship, not even close. Could you have a flash that destroys the turret by igniting the powder inside? Possibly, but the game isn’t simulating that. 

Now if we get a detailed below decks damage model, then things like this become reasonable. But this whole conversation goes back to Masonator’s losing a BB with max torpedo protection (or at least that’s way it came off) to a single torpedo. It just didn’t happen and shouldn’t with game modeling as is. I can only hope the devs do give us a better model here, since magazine detonation due to fire effects happened far more often.  

 

There are no good TDS designs of this period. They do not exist. Not a single one from any nation could be deemed good.

>My point in this thread is barbette armor should not be a factor in ammo detonations from torpedo hits. Anti-torpedo selections should reduce it.

I could agree with that.

 

>What point are you trying to make here? All I said was to punch through the empty/flooded space of a torpedo bulge, then make it through the actual belt armor to hit centrally located main magazines and cause an explosion is beyond remote.

My point was there are absolutely torpedoes out there that could cause issues. American torpedoes were not very good in many ways. if a 21" torpedo reached the magazine, what happens when a type 93 hits with far more TNT.

 

>considering there are no examples I have seen or heard.

Heres a video of it happening, HMS Barnhem sunk via U-331. The ship was doomed anyway, but cleary the magazine does explode. The cause is now believed to be a magazine explosion from the 4" mag, which chained into the 15" mag.

 

Edited April 14, 2020 by Hangar18

[Steeltrap]

With all due respect, I consider the explosion of poor old Barham to be a red herring, one that has come up more than once.

All it shows is that an uncontrolled fire could produce a chain of events to trigger the explosion of either the propellant and/or shell magazine(s). Is that news?

Given what happened to Yamato, and possibly others I can't recall off the top of my head, I'd suggest that's ALL it proves.

The trouble is there isn't a SINGLE case of a "more modern" major capital gunship (by which I mean BC/BB) suffering a catastrophic destruction through torpedo strike exploding some element of the propellant/shell magazines.

If anything, all available evidence suggests those capital ships from WW1 and beyond were able to prevent such an occurrence unless the conditions on board meant damage control was no longer possible.

There's the case of USS North Carolina who took one of what was considered by all to be the most damaging of all WW2 torpedoes, a submarine launched IJN torpedo, more or less abreast one of her forward main gun turrets. Yes, the TDS failed in that it was supposed to prevent damage reaching the internals of the ship, especially critical areas such as all areas of a main gun turret's operation (thus the magazines, shell/propellant handling areas, and the whole turret trunk), yet didn't. Even WITH that, however, rapid and appropriate damage control actions prevented any result worse than a small loss of life (not wishing to downplay that of course), a temporary significant list to port (about 10 degrees from memory?) and the knocking out of that main turret until a return to port for repairs.

[As an aside, that single salvo of 6 torpedoes caused the loss of USS Wasp (its target) yet also travelled into another CV formation miles away (!!), hitting the DD USS O'Brien (sank some weeks later, apparently due to structural effects) and USS North Carolina. 5 hits from 6 launched, causing all sorts of critical damage. Surely one of the most devastating torpedo salvoes every launched at a naval formation in the whole of the war. There's a great page that covers the effects on North Carolina, including interviews and the like. I highly recommend it.]

I had raised elsewhere that it seemed a very poor choice to introduce this mechanism BEFORE addressing the KNOWN problems with compartmentalisation and armour etc precisely because what we're seeing happen was always going to happen.

I AGREE with it technically being possible, and if you build a capital ship with no significant thought to torpedo mitigation you ought to be taking a very real risk, but the problem is you as things stand you can do "all the right things" and STILL explode and sink because "all the right things" do NOT address the elephant in the room, namely magazines outside of what the armour system considers 'the citadel'.

The counter-argument is perhaps this is the best time to test it precisely due to these shortcomings, ironically enough, because it will show very clearly that it is working as intended. Perhaps indeed that's why they did it. My thanks to  @arkhangelsk for reminding me to look at things in this sense (and, to be clear, that's not said with any sense of irony).

An illustration makes the issue pretty obvious:

A 2"/50mm shell causes 2,926 damage to this CA [edit: I had written it was a CL, yet this highlights even more the problem with the extended armour zones and magazines]. Note the 9" HE over-pen that does a whole 9.6 damage. This is why I DO mount those silly popguns on lower tech level ships because the whole damage and compartmentalisation system conspire to make them utterly, ridiculously dangerous to low armoured ships, more so in many ways than more common secondary armament calibres.

If a 2"/50mm gun can do this at 4km, imagine a torpedo hitting the same 'extended' armour zone where the magazines may be. Then consider we can do nothing to move the magazine within the citadel protection. Then ask whether they really ought to have done this the other way around, namely fix the armour/compartmentalisation THEN allow this function.

Having said all that, I'm not really fussed either way.

Until this issue of armour/compartmentalisation/damage is addressed, I find little value to playing. As is true for most of us, I expect, I understand the systems we have well enough to know what ships are going to be a threat, what aren't, and equally what will be a pain in the *** to kill v those that might go "bang" fairly easily.

None of which is meant to "choose a side", or suggest anyone is "right or wrong" (I would use "correct or incorrect", as being an old school user of English I consider the inherent moral element contained in right/wrong to be inappropriate when discussing matters of fact or possibility, thus correct/incorrect are the better words, LOL), or indeed to "bash the game".

It's all good, well-intentioned discussion as I see it, and I try my best to view everyone's contributions in that light.

Besides, it's a happy way of spending time that mitigates any frustrations from the health directives under which I am living ("do not leave your home unless it's for the following, 'necessary' purposes").

Hope everyone's safe and well.

Cheers

Edited April 15, 2020 by Steeltrap
added link to a page on USS North Carolina re torpedo damage

[madham82]

8 hours ago, Hangar18 said:

There are no good TDS designs of this period. They do not exist. Not a single one from any nation could be deemed good.

>What point are you trying to make here? All I said was to punch through the empty/flooded space of a torpedo bulge, then make it through the actual belt armor to hit centrally located main magazines and cause an explosion is beyond remote.

My point was there are absolutely torpedoes out there that could cause issues. American torpedoes were not very good in many ways. if a 21" torpedo reached the magazine, what happens when a type 93 hits with far more TNT.

 

>considering there are no examples I have seen or heard.

Heres a video of it happening, HMS Barnhem sunk via U-331. The ship was doomed anyway, but cleary the magazine does explode. The cause is now believed to be a magazine explosion from the 4" mag, which chained into the 15" mag.

 

No good TDS as you say is a bold statement that is more a matter of how you see it, than how designers see it. Yamato and Musashi both took many torpedoes to sink, even with their design weakness. NC, by the own Navy report, took damage that was in line with their expectations. All of these are successes if you view it from the designer's perspective of the ship not sinking from a single hit. It just depends on what your expectation is for these protection systems. The key thing to remember is there is no perfect system, since it is all a balancing act of protection, speed, cost, and weight. The Yamatos protection emphasized protection from plunging fire over torpedo protection for example. That one didn't work out too well for them in the end. 

@Steeltrap laid it out well. Barham sunk 4 minutes I believe after being torpedoed due to fires (started by the torpedo hits) reaching the magazine. This is what we really need to simulate. It also happened after it had rolled over on it's side. In the game, that basically would be a post-sinking explosion too. 

[disc]

Probably the torpedo protection of the Richelieu class of battleships would be considered very good, or indeed the best of the modern battleships.

At 3.5m below waterline, the maximum depth of the torpedo belt was about 7 meters (amidships), and its minimum depth was about 4.12m (forward armored bulkhead). Additionally, there was a wiring passage traveling the length of the citadel inboard of the holding torpedo bulkhead, with a thin bulkhead inboard of that, so its ~1.2m depth could be added as some extra minor protection. Finally, refits added a 1.27m (maximum, presumably) bulge to the exterior of the ship. Therefore, the maximum torpedo protection reached 8.25m, or 9.45m counting the wiring passage. This was generally superior to Yamato, which had about 5.5m amidships, or Iowa, approximately 5.8m amidships.

As there was not much stiff armor, there was limited protection against diving shells. Armor has some positive effect in rejecting torpedo fragments and blast, but it is not flexible and may be a source of fragments itself. Extra armor was indeed used on Richelieu in narrower regions, such as around the magazines, where depth was considered insufficient.

Richelieu had some other features that added to the torpedo protection.

• The magazines had a triple bottom.
• There was water-excluding rubber foam ("ebonite mousse") in some compartments, including a large compartment forward of the citadel.
• Subdivision was considered very good.
• The boiler and turbine compartments did not have a longitudinal centerline bulkhead.
• The boiler and turbine compartments alternated.
• There was a strong armored deck.

However, the design was not perfect.

• The machinery only had a double bottom.
• Some of the bulkheads were too close to one another.
• The citadel proper and torpedo protection belt covered only 54.2% of the ship length.
• The water-excluding foam was highly flammable.

This system was not put to the test. Before refit, it was considered proof against 300kg of TNT, but this was a conservative estimate. After refit, it was thought good against 500kg TNT. Dunkerque, which had a similar layout, successfully rejected depth-charge damage against the belt, so that French designers were satisfied.

[Hangar18]

13 hours ago, madham82 said:

No good TDS as you say is a bold statement that is more a matter of how you see it, than how designers see it. Yamato and Musashi both took many torpedoes to sink, even with their design weakness. NC, by the own Navy report, took damage that was in line with their expectations. All of these are successes if you view it from the designer's perspective of the ship not sinking from a single hit. It just depends on what your expectation is for these protection systems. The key thing to remember is there is no perfect system, since it is all a balancing act of protection, speed, cost, and weight. The Yamatos protection emphasized protection from plunging fire over torpedo protection for example. That one didn't work out too well for them in the end. 

@Steeltrap laid it out well. Barham sunk 4 minutes I believe after being torpedoed due to fires (started by the torpedo hits) reaching the magazine. This is what we really need to simulate. It also happened after it had rolled over on it's side. In the game, that basically would be a post-sinking explosion too. 

Shinano I went down with 4 torpedoes.

Air dropped torps do not carry very much explosive power in comparison. Yamato and musashi both received far more hits than what was needed. Musashi was crippled by the first few alone. Yamato only survived because torpedo hits counter flooded.

The TDS on these ships was not good.

Edited April 15, 2020 by Hangar18

[Steeltrap]

How about Bismarck?

My recollection is her TDS succeeded in preventing any damage making it through the armour scheme inboard of the TDS. In other words, the TDS area flooded, but nothing else. Isn't that more or less the definition of a successful TDS?

It's certainly different from NC for starters, although yes they were air dropped RN torpedoes and not the more potent IJN submarine weapon.

I wrote a pretty firm critique of this change in potential for torpedoes back when it was first included in what was then the upcoming new version. I decided not to post it, but I will include a little bit:

I spent some time looking through the list of all the BBs I could find ever to have been sunk, regardless of cause.

Having done so, I found the data supports the following conclusions:

By FAR the greatest EFFECTIVE danger posed by torpedoes was rapid, uncontrolled loss of stability leading to capsizing.
MUCH more common, however, was flooding that exceeded pumping capacity and that damage control was unable to halt, ultimately causing the ship to sink.
 

Magazine explosion due to torpedo strike, NOT an explosion from fires when the ship was already sinking and no damage control efforts were possible?  ONE, the French pre-dread Suffren that DID explode and sink more or less 'immediately' (the u-boat responsible surfaced shortly after and found no survivors), more or less as with HMS Hood (same catastrophe, different cause).
 

Much the same is true of BBs hitting mines.

In summary, my main issues are the threat applies even to "well protected" BBs, we don't know HOW or what chances apply, and real world evidence points very much in the opposite direction such that it ought to be VERY unlikely IF you spend the resources on TDS. This is EXACTLY the sort of thing in patch notes that drives me nuts, LOL.

It still strikes me as "a solution in search of a problem", one that can add nasty consequences that are at direct odds with as much available info as I was able to examine in a few hours. If others can point to evidence that says otherwise, I'll be all ears (well, eyes, 😜 )

Cheers

p.s. I didn't post it because I concluded it was going to be included no matter what I said, and regardless of the vast amounts of real world evidence pointing to it being a theoretical possibility that could 99.99% be summed up as "never happened, why bother?". As they'd done the development required, I figured they weren't going to be interested in me pointing out a host of reasons why it seemed a poor choice of time and effort in face of far more significant things that could have been done.

 

Edited April 15, 2020 by Steeltrap

[madham82]

9 hours ago, Hangar18 said:

Shinano I went down with 4 torpedoes.

Air dropped torps do not carry very much explosive power in comparison. Yamato and musashi both received far more hits than what was needed. Musashi was crippled by the first few alone. Yamato only survived because torpedo hits counter flooded.

The TDS on these ships was not good.

Shinano was sunk because of a combination of weak protection on the stern (we discussed earlier) and lax Japanese reaction to the damage. They continued on a full speed after the hits which pushed more water into the hull, and they didn't really bother countering flooding or pumping until too late. It also took over 6 hours to sink. Compare their reaction with how the NC's crew reacted after being hit. The US Navy had performed studies that showed immediate reactions to torpedo flooding and counter acting any list was the key to mitigation. The Japanese were overconfident in their design and knew US torpedoes had smaller warheads than theirs, so they wrote that off too. It cost them obviously. 

You are correct about aerial torpedoes power, but the sheer number would translate to 4 or more standard torpedoes. Also you have that backward, Musashi lingered b/c the US planes hit both sides. They learned this mistake and did not repeat it on Yamato...which still absorbed an inordinate amount of damage before capsizing. 

Again good is a subjective term. I mentioned in the last reply it was compromised for plunging fire, something we really don't have that level of modeling in the game. So it was not perfect if that's what you mean by good. 

[RAMJB]

On 4/10/2020 at 9:14 PM, madham82 said:

What point are you trying to make here? All I said was to punch through the empty/flooded space of a torpedo bulge, then make it through the actual belt armor to hit centrally located main magazines and cause an explosion is beyond remote.

Yet there are multiple instances of big battleships ordering the flooding of their own magazines to cancel out the danger of a magazine going off due to a torpedo impact. One famous instance was Scharnhorst when she was hit by Acasta; the blast not only caused extensive flooding but jammed Caesar and produced a lot of smoke. The crew feared something had caught fire and the order was issued to preventively flood the turret's magazine because of the risk of detonation. Though it was reversed shortly thereafter when it was certified no fire was ongoing.

Unlike many opinions seen around here ,a magazine going off due to the damage caused by a torpedo hit was a real threat and possibility, even in big ships with big torpedo defence systems. Was it likely?. On ships with big beams and good enough TDSs it wouldn't be likely, no. Was it possible even then?. Certainly it was.

As for cruiser TDSs, some of them had torpedo bulkheads and some sort of layered protection. But even then they were terribly vulnerable - one of the key features of any TDS was depth, and cruisers, being far less beamy than battleships, never had any kind of really effective TDS with enough depth to significantly reduce torpedo damage.

Edited May 2, 2020 by RAMJB